Braking mechanism



May 14, 1935. F. A. JIMERSON BRAKING MECHANISM Filed July 1v, 1930AINVENTOR.

idrimena/z 78 H15 A TTORNEY.

Patented May 14, "15935 Y BRAKING MECHANISM Y n y Francis A.l Jimerson,Athens, Pa., Yassigner. t9 Ingersoll-Rand Companys; Jersey City,N.AJ.,Ya.-V corporation of New Jersey, I, I. f r VVApplication July y17,1930.,"'Serial 2 Clarins.4 (o 1 !v1s8'`s'2 )j V n I'his 'inventionrelatesto hoists and more particularly to a braking device-for the same,

Y One objectv of the invention is to maintain conftrol of thev load vatall times and prevent it from 5 dropping rapidly when not being raised.'y

y Yi5 j Another object of the invention is jto 'I'nade said brakingdevice automatic and operable as soon as the load begins to drop. iOther objects of the' inventionwill be in part obvious and in partpointed out hereinafter.

[Inithe drawing, l Figure 1 is a longitudinal the vimproved hoist, and Yo,

vFigure 2 'isa sectional View taken on line `22 ofFi'gure1.` v Y j `lThis .invention more particularly contemplates ,the v.provision of `acontrolling brakemechanism to be applied to a hoist which is driven,byan' sectional view through electricmotor as distinct yfrom a hoistwhich is driven byV anhair motor of the piston type. In the 'latter itwill be obviousthatV as soon asthepower WhichV was applied'for raisingthe load was cut off the motor' itself automatically actedv as vapowerfulbrake and thus prevented the loadafroin rapidly dropping., When'a hoist'is driven by an electric motor, however, and the currentis cutoff Wh'en the load is' raised,I there is nothing to prevent ftheloadfrom dropping; rapidly except i3d the inertia of the parts. "Ihespeed ofthe dropping' load would, under these conditions, accelerate veryrapidly and easily become sufficient to wreck the armature bycentrifugal force.V This-'serious disadvantage has been overcome in myinvention by a simple braking device which is automatic in `its action,vand practically instan- ,taneously effectiveaas soon as the loadbeginsVto drop.: y Y u f Referring to the drawing whereinA similar charactersof reference denote corresponding parts throughout, II) designates vthebase frame of my improved device which is adapted to support both thehoist I2 and. the motor I4 for driving the holst. The motor I4 may be ofthe .electric type havingafuniedirectional of othermotion The armatureshaft I6 of the motor is supported the usual end cover I8 by means ofthebearing `20.

Suitable means are provided forcoupling theV hoist I2 `to the motor I4and inthisinstance the Varmature s'haftffIBv has a projecting end formedwith a series of splines 22 extending longitudiandthe splined shaft I 6enters this coupling'` for ,a short distance. ,Y Intothe otherendoffth1s V-'eorir'iling 24fis securedin asimilarnannerf the A'main' s haft26 ofth'efh'oist |712', fj j ,Y v Thejother 'end' of the 26lis-'supportedina y bearing Z8 carried by, a "cover 30 which encloses e"5 'l that endoff the hoist |25 TheimainshaftfZB A driven in this wayatthegspeedofgthejmotor due toth'e' direct couplingto the -armatureshaft I 6. This speed l is preferably "reduced 'before being Ylapplied'to raise a load byafsystemlof reduction `10 gearing operatedby* afpinion A32 suitably `keyed.

to the mainfshaft 26A adjacentthe`V QOVQIIII). Meshing vv'ithfthelpinionV 32V ajrelatively Vlarge y eazr:3ft-with a pinior36 adapted torotate at similar speed and Aforthis-'p'urpos e `laeingfio'rmed. inthisinstance integral withy thelarge gear 34 andjsupported in conjunctionvtherewith upon the shaft 38. The shaft" 38 is4 Supported atheney end'inthe cover 3B -byra bearing and at theother endV -o by a' bearing j(42which is securedin afh'ousingjy v20 enclosingthese'qgealrs,rAIhejhousing is secured by focuses mulebasen),`

Meshingwith the pinionl is a `larger gear .46 'whichjis suitablykeyedftov a hollow shaftl. t. The vhollow shaft 48 willI therefore bedriven 25 through the reduction :gearing atV desired relative Sped t9thev main" Shaft 12.6 .depending Vupon the chosenratio of-these gears.Thegear46 is maintained in'position on the hollow shaftf'48 ,-5 I oy avrnut Ywhich holds it against a bearing 52 'V30 supporting the hollowshaft 48finthe'housing 4,4. A ange A54 on the housing 44 extends atthe'fother side fof the bearing 52 and abutting thsflange' isabraledrum'member 56 supported onvthe d hollow' shaft 48 by abearing'58."o 35 '7"I'he`brake drum member 56'has an 'external vbraking surfacelil),` upon :which a brake .band1l62 i isadapted to act and preventitsrotation witlzrtheV hollow. @shaft4 4.8.' ,"I'lie brakaband mechanism54D I comprisesja band lI54fpreferably of metalsecureid Y tofthe brakebandA 62,y which is iprefer'aiblylgo'f a j friction material; and thismetalfb'arld"f 64' is Vanchored at'itsiendsto 'A pins 66 rcarried"bysup;Y ports k68Y on the casing "I0, LOne of the supports Vv68Vpreferablyhas ajleft;V hand thread 1,0 andthe othersupportpreferably has alrighthand thread 12." Ajjshaft 'I4Vhaving 'right andleft hand threads thereonis inserted inthe supportsBBand' extends through a bearing 16 vorrthecasinglllwherea handle'l may besecuifedthereto.H Thesupports '68;f`a'rearranged.' jslideways vlill soythat they can movetowa'rds aniffa-vvayfromeachothr inithe casing I, 0 when the shaft'j'l4'-zis -rotatleldf 11nY one direction :or vthe other; "I

A portion of the brake drum 56 extends beyond the braking surface 60 andhas aninternal gear 80 formed thereon. Meshing with this internal gear80 is a drum driver comprising a plurality of pinions 82 arranged inplanetary fashion. These pinions 82 mesh with a pinion 84 suitably keyedto the hollow shaft 48.

A winding drum 90, which is adapted to accommodate the Vhoisting rope 9|carrying the load to be raised, is supported upon the hollowy shaft 48around which it may be driven by the drum driver.

To this end the winding drum Sil-'has a iiange abutting the braking drum56 and into this flange projects a plurality of stub shafts 92'. Thevother end of each stub shaft is supportedin a hub 94- on a Vcover 95which is secured to the winding drum by bolts 88.Y Theplanetarydrum'rdriver pinions are free to Vrevolve on the stub shafts 92 whereonthey are supported by frictionless bearings-86e i f i The. Windingdrumli rotates freely. on the hollow shaft 48 and i s -j ournaled at thedriven enden a hearing 98. titiller;v abuts a-shoulder.

the Shait-.r ,It Willbe ,Seen from this Construction thatl when` the nut0wat the end of the hollow shaft 48 isV dl'WIl 11D tightly Vall thepartsbetweentheshoulderfl 00 and the nut will be held Y seurely in. Desmonf Areduced portion |02 on. the hoisting drum is mended in Order'that therope 9| may. be wound therearound, andgin order to keepthe rope inA.position asecond-flange |06 isA provided Yat `the oftherend of thereduced. portieri |02. This end Yof the drum-90 having the iiange1|06 issupported ontle *hollow` shaft bya bearing |88 which abuts asedpeisnoulde; :menthe shaft 4 8, Extendingffrom the Harige-|016. is aprojecting portion 2 inthe form of a hubhaving threads 4 on itsperiphery. The threads ||4 in thisk instance *may` be right-hand..Theinner surface of the Y gagingr the 'thread I I4. The clamping'vmember |24"is preferably spaced from the'iian'ge |06 on the, hoistingdrum and fbetween these two members is a frictionmember Y|26 havingclutch facings '|28 'of some friction material projecting Von l eitherside thereof and secured in position by the rivets |30. The frictionmember |26 hasan an- 'nularange ori its periphery forming aA braking"surface '|32'.Q4V The (braking surface |32 is similar tothe brakingsufaceBD at the' other side of Athe hoist'ffand has ar similar.brakeband 62 acting thereon, The mechanism for manually operatingthissecond brake is Videntical withthat emtljiesame at this point is'`therefore. omitted. e

Thel friction member. |26 is preferably sup- "por-ted ,forfree rotationupon the clampingv member.|24 bymeans'ofa projectinghub |34 vengag-Attached by its. outer end to the clamping member |24 is a spring |36 ofthe Ldat spiral type, 1186,/-

vforth of the clamping member ing its inner end engaging the hub 2 onthe winding drum. This spring is adapted to be placed under an increasedtension and released from such by longitudinal movement back and willcause the pinion 84 to rotate the pinions 82 of the planetary drumdriver.

If the brake 62 has not been 1tightened upon the bra-ke drum 5S thevdrum driver will merely rotate the brake drum 56 Without in any waymoving the winding drum 90.

They brake 6.2.- is thereforetightened upon the brakedrum 56 to preventits rotation, whereupon the pinions 82 of the planetary drum-driver willroll around the internal gear 80 and cause the the rope 9| will windthereon to raise the` load. VVVThe othervband brake |32 has beentightened upon the frictionl member |26, preventing its rotation withthe drum. As the winding drum revolves thvelclutch facings |28.wi1lfrictionally engage the clamping Ymember |24 holding it againstrotationv andthe thread ||4 being right-handed will move it away fromthe winding drum against the tension of the spring |38.. The spring |36will now commence to wind up and at a certain point the increased4tension thereof will overcome the, friction exerted/by thelclutchffacings |28 upon the. clamping member 24 to permit the windingdrum to rotate the clamping member around the clutchv faeings |28.4 Theclutch facingsA are, of course; heldimmovable by the tightened brakeband. 62 acting .upon the braking Vsurface |32. YTheload canvtlriereiore be hoisted to anviheight. e When the load has stoppingrotation of the. windingvdrum ina clockwise direction and permitting thekforce ofgravity toact uponthe load vto move the drum in the oppositedirection by meansof the rope 9|. As soon as thedrumstarts torevolveinthe opposite direction the vincreased tension on the Aspring |36 will berelaxed thus permitting the clutch facings |2Y8 to gain lcontrolandfrictionally rotate the clampingmember |24 moving it back longitudinallyalong the thread |4 inthe direction of the flangeY |06 on the windingdrum. longitudinal movementwill continue for a brief instant and thenthe clamping member |24 will forcefthe clutch `facings .l 2 8 againstVthe flange vv| 06lcreating 4a braking action `which becomes continuallygreater Vuntil movement of the winding drum ceases It will readily beseen that the braking action of the clutch facings |28upon the windingdrum will occur almost instantly Fwith .the dropping of the, load andthat thewinding `drum can Y attain no :great speed beforethisv` occurs.ployed foroperatmg the first anda description of If it isdesired tolower the load,` thiscan be done .by gradually .releasing the brake band62 onthe Africtionmember |26 and `controlling the,

h istsj'h heen.. provided, While .-thegbrakng |24 on the Y y beenhoisted to desired:

height the vmotor may be entirely cut off thus Y v Vincorrere device hasbeen described in connection with `an electric motor drive, it will beapparent that 'its use is not confined to this type, but may be appliedto other forms of drive with equal facility. The braking action ispractically instantaneous with the dropping of the load and is entirelyautomatic. I claim:

1. A brake for a rotary member, comprisingspiral spring connected to themembers and being subjected to tension during rotation of the membersand acting upon cessation of rotation or thev members toV eiectfrictional locking engagement between the friction means and.` bothmembers. Y

2; A brake for a rotary member, comprising non-rotary Vfriction `meansadjacent the rotarymember and movable longitudinally with respectthereto,` a clamping member rotatable with the rotary member and beingheld released from the friction means upon rotation of the rotarymember, a spiralrspring connected to both members Y for clamping thefriction means into frictional engagement with both members uponcessation of rotary movement of the members, and brake `means forlocking andreleasing the `friction meBlnS.

FRANCISVA. JIMERSON.

